Method of estimating the baking qualities of doughs



Dec. 23,1941, P. HALTON METHOD OF ESTIMATING THE BAKING QUAL'ITIES OF DOUGHS Filed Jan. a1, 1938 s Sheets-Sheet i vE/v-ra/e. #0; TON

9 7 v'o/evv P///L /P 23, 1941- P.'HALTON 2,267,561 "METHOD OF ESTIMATING THE BAKING QUALITIES 0F DOUGHS Filed Jan. 51, 1938 3 Sheets-Sheet 2 Dec. 23, 1941. I P. HALTON' 7,

METHOD ESTIMATING THE BAKING QUALITIES OF DOUGHS Filed Jan. 31, 1958 3 Sheets-Sheet 3 v Q T 7RNE VS Patented Dec. 23, 1941 i Application new, 31,1938, Serial No. In G eat Britain March 23,1931

name

3 Claims. items-s1) The present invention relates to a method oi estimating the baking qualities of a Wheaten flour dough.

It has been found that a dough of baking, a,

qualityshould have a high ratio of viscosity to elasticity modulus and that it should also have a low tendency to tear, and it isman object of the present invention to provide an improved process for estimating these qualities in a dough. ,Now;

the force required to stretch a dough depends extrusion process can be used also "for-ascertaining correct-bakehouse absorption of flours.

Apparatus.- suitable for testing dough in ac-,

cordance with this invention is shown inthe accompanying drawings in which:' a

Figure 1 is a plan-yiew and Figure 2 is aside elevation 01 apparatus forestimating the elasticlty modulus; o1 dough, Figure 3 is-a' side both on its viscosity and on its elasticity modu- Ins and a further object of the invention is to, provide a method for making up sample doughs values for elasticity modulus so that their viscosity/elasticity moduli ratios can be determined by measuring the force required to stretch. the doughs. 3 s U According to the present invention the improved process for determining the quality 01' a,-

dcugh comprises making ,up adoughuwith a water content such that its elastic modulus isthe same as that oia dough having a known and suitable water content.

According to a feature of the present inven tion the improved process for estimating the bakingqualities of doughs comprises making doughs of predetermined and similar elasticity moduli, and testing the doughs for their viscosity/elasticity moduli ratios and tearing properties by measuring-the forces required to stretch samples of the doughs and the. elongations produced by the force before rupture occurs. v

The elasticity modulus 01' a dough is a function 01' its water content. A method of estimating the water content necessary to produce doughs of similar moduli may comprise'measuring the rate of extrusion of ajdough through an aperture under the influence 01' a standard pressure, since from different flours which shall havesimilar elevation of apparatus forestimating the vyis- 1 cosity/elasticity, moduli ratio and tearing properties of dough,.andFigures. 4, 5 and 6 show some i representative curves obtained on the apparatus shown in Figure 3. Referring now to Figures 1 and'2 a cylinder II.

is secured to ;the plate I! which -.is mounted onv the uprights l3 bymeans of levelling screws I4 it has been found that doughs 01 similar times of extrusion have similar values for elasticity modulus.

It has further been found that the water contents which, in different doughs, produce similar elastic moduli bear a constant relation to the most suitable water contents (absorptions) for bread-making. Thus, if the correct water absorption of optimum bread making be given to a dough and the time of extrusion be determined,

absorptions ior bread-making. Hence the same so that the cylindermay be arranged with its axis vertical. The cylinder is closed at its lower end; except for a small aperture l5, and'within the cylinder is a tightly flttin'gpiston l6 whichhas arod i1 securedto its underside, passing through the aperture IS in the cylinder, and to-which is attached a weight l8. A pointer is is fastened to the lower end of the rod l1 and co-operates with a fixed verticalscale 20. In order to estimate the required 'water'content of a dough a sample thereof is introduced within the cylinder ll beneath the piston is. The force of the weight on the piston l6 causes dough to be extruded through the aperture IS in the cylinder ii and the rate of this extrusion, which is a function of the elasticity modulus of the dough, can be measured by the movement of the pointer I! over the fixed scale 20 in a given time or by the time taken by the pointer I9 to travel a given distance. Hence by measuring the rates of extrusion of doughs made up with different quantities 01' water the amount of water required to be added to samples of flour to give doughs of predetermined and similar elasticity moduli may be determined. I

The viscosity and tearing properties of a dough may be measured by means of the apparatus shown in Figure 3 which comprises two horizontal arms 2| and 22 other, e. g. in a vertical direction. The lower arm 22 is mounted on a crosshead 23 carried by two vertical guides 24 and can be moved up and down by means 01' a vertical screw threaded rod 25 engaging with a threaded sleeve 26 fastened to the crosshead 23. The screw threaded rod 25 may be rotated by means of a small electric motor 21 connected with the rod by means of a belt 23 and pulleys 29, 30 or the like. The upper arm 2i is mounted on a crosshead II carmovable relatively to one an-,

ried by the two vertical guides 24 and is normally supported against a fixed upper stop by a wire 32 passing over and rigidly connected with a pulley wheel 33 to which a weight 34 is attached by a rigid arm 35. If desired a spring or other suitable means may be used to support the upper arm 2| and crosshead 3| against the stop instead of the wire and pulley system shown. The upper arm 2| also engages with one end of a pivoted arm 35, the other end of which carries a pen or like stylus, to record the vertical movement of the arm on a drum 31. This drtun 31 is rotated by gearing from the upper end of the threaded rod- 25 and-themdegree of rotation. is thus a measure of the distance through which the lower arm 22 has moved. In operation the lower arm 22 is iirst moved upwards until it is just in contact with the upper arm 2|. In this position a ball of dough, made up as previously described so as to have a predetermined elasticity modulus, is impaled symmetrically on the two arms and the motor 21 is then started so as to move the lower arm 22 downwards. The up" per arm 2| will tend to be pulled/downwards against the action oi the weight fl owing to the viscosity of the dough and the tension exerted on the dough will be recorded on the drum 31. Ultimately the dough will tear apart and the upper arm 2| will spring up and record on the drum the point of rupture. There will thus appear on the drum a record of the force required to stretch the dough and the elongation produced in the dough by this force.

Since the doughs were made to have predetermined and similar elasticity moduli it is thus possible to estimate their viscosity/elasticity moduli ratios and their tendency to tear from which data their baking qualities can be determined readily. For example, a curve such as A in Figure 4, wherein the. lines a represent the viscosity/elasticity moduli and b the extensibility, indicates that the dough has both a high viscosity/elasticity modulus ratio and good extensibility. This signifies that the flour is at very good baking quality.

On the other hand, a curve like B, Figure 5, indicates low viscosity/elasticity modulus ratio but good extensibility. The low viscosity/elasticity moduli ratio signifies that the dough is weak and lacking certain desirable features such as spring and stability which are required bread-making purposes.

Curve C, Figure 6 indicates medium viscosity/elasticity moduli ratio but poor extensibility. While the viscosity/modulus ratio would be high enough for bread-making purposes the poor extensibility shows that the dough tears easily and on this account would be unsatisfactory. It is known to test the elasticity of a dough made up from a sample of flour mixed with a constant percentage of water, by submitting a layer of dough of a predetermined thickness to air pressure until it bursts and calculating the required characteristics from the pressure at which burstior ing takes place but it is to be observed that in accordance with the present invention, samples of doughs of predetermined and similar elasticity moduli are prepared and the testing operations are purely mechanical and not pneumatic and can be applied even to an aerated dough.

I claim:

1. The method of estimating the baking qualities o! doughs, which comprises estimating the water content necessary to produce doughs of similar elastic modulus 'by measuring the rate of extrusion of the doughs under a predetermined pressure, and then determining the ratio between the viscosity and elastic moduli of said doughs.

2. The method of estimating the baking qualities of doughs, which comprises estimating the water content necessary to produce doughs of similar elastic modulus by measuring the rate of extrusion of the doughs under a predetermined pressure and then stretching the doughs under predetermined tension and at a rate until reaching the breaking point of the dcughs to determine the viscosity moduli and extensibility characteristics of the doughs, and thereby ascertaining the ratio between the viscosity and elastic moduli of the doughs.

3. The method of estimating the baking qualities of doughs, which comprises making up samples from difierent flours with varying quantities oi! water content so that all samples will have the same elastic modulus, determining the viscosity modulus of each of the samples, and determining the ratios between the viscosity and the elastic moduli of the various samples.

PHILIP HALTON. 

